Digital signals are typically routed through a circuit, for example an integrated circuit, using active multiplexers which employ logic gates comprising transistors and other active components. These multiplexers can be used for example to select between different clock sources or other digital signals. One problem with the use of such multiplexers is that the active circuitry upon which they are built can contribute significant noise which may limit the phase noise floor of the signal, and consequently the jitter of a clock signal. Certain applications, such as high-performance data converters, frequency synthesizers for electronic warfare systems, and high throughput microwave backhaul systems, to name a few, generally require clock sources with extremely low jitter.
Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications, and variations thereof will be apparent to those skilled in the art.